EPA’s Chemical Risk Assessments Rely on Flawed Science, Study Finds

A new study concludes the U.S. Environmental Protection Agency’s Integrated Risk Information System (IRIS), a program assessing the toxicity of chemicals and any risk from exposure to them, often produces assessments based on flawed research.

The U.S. Environmental Protection Agency’s (EPA) Integrated Risk Information System (IRIS), a program assessing the toxicity of chemicals and any risk from exposure to them, often produces assessments based on sloppy or flawed research, a new study concludes.

The study’s author, Angela Logomasini, a senior fellow with the Competitive Enterprise Institute, found IRIS has a long history of producing or citing poorly conducted risk assessments that lack transparency. All too often, using these faulty assessments, EPA has advanced flawed, counterproductive regulations that raise the costs of producing and using beneficial chemicals, Logomasini found.

Even when the federal government or state governments don’t use IRIS’s assessment to ban a particular chemical, the flawed results often result in unwarranted health scares that dissuade the public from using effective products, the study published by CEI reports.

Overly Cautious Assessments

EPA developed IRIS in 1986 to provide an agency-wide evaluation of chemical risks for use by all of EPA’s departments in assessing the need to regulate chemicals people may be exposed to. The goal was for IRIS to establish regulatory baselines for the concentrations and the appropriate use of chemicals to minimize risks associated with exposure to them.

Logomasini found IRIS has been “excessively cautious” in its assessments.

“EPA risk assessments, by and large, focus on preventing worst-case scenarios—even absurd ones—and ignore more plausible scenarios, while ignoring more serious risks created by the EPA’s own regulations,” Logomasini writes.

EPA identifies four steps necessary for an accurate risk assessment. For “Hazard Identification,” researchers consider whether a chemical has the potential to cause harm at some exposure level. A “Dose-Response Assessment” ascertains whether there is any relationship between exposure to the chemical and health conditions. “Exposure Assessment” analyzes whether the dose-response evidence shows a connection between a health risk and a chemical, and if so, at what level of exposure. “Risk Characterization” uses information collected in the prior three steps to assess actual risk levels based on realistic assessments of the public’s exposure to the chemical.

IRIS conducts only the first two steps of the risk assessment, yet based on this incomplete assessment it ranks the potential carcinogenicity of chemicals and estimates non-cancer risks. IRIS’s rankings are often based on research that lacks transparency, resulting in other researchers being unable to confirm the assessments by testing the underlying data, Logomasini reports.

Not the Gold Standard

Proponents tout IRIS as the most comprehensive, accurate chemical risk assessment, but it is not, says Logomasini.

Logomasini cites IRIS’s assessment of the chemical ethylene oxide, which is commonly used to sterilize medical equipment, as one not based on good science, which may cause hospitals to use less-effective sterilization programs and potentially put patients at risk of infection or illness from exposure to unsterile equipment.

“IRIS’s 2016 assessment for the chemical ethylene oxide (EtO) set a standard that is 19,000 times lower than levels of this chemical produced in the human body, which is ridiculous,” Logomasini said. “As result of this excessively cautious standard, the State of Illinois shut down a facility that uses EtO to sterilize medical equipment.

“There is no evidence trace levels of EtO found in a few areas near the plant have harmed anyone, yet the Illinois prohibition, based on EPA’s IRIS assessment, may end up killing people by exposing them to improperly or incompletely sterilized medical equipment,” Logomasini said. “Unwarranted fear of minute exposure to EtO has led to needless bans and regulations that could wind up being deadly.”

‘Linear No Threshold’ Threat

EPA uses toxicology poorly to make people believe substances they may be exposed to are more dangerous than they really are, says Dr. John Dale Dunn, an emergency physician, researcher, and policy advisor to The Heartland Institute, which publishes Environment & Climate News.

“Citing IRIS, EPA uses schlocky, junk toxicology to create health scares, making people think the whole world is a dangerous place, when in fact the Earth is a very safe place,” Dunn said. “Ambient levels of even the most awful toxins are not levels where you can say people face a terrible risk from exposure and they should be concerned about it.”

Dunn says IRIS’s assessments do not meet baseline conditions of good epidemiology for proving a substance causes illness in certain populations.

“In order to have what is called robust research evidence of causation, you have to have at least a doubling of the rate of illness in the studied population,” said Dunn. “In order to prove causation, you have to have higher rates of association—three times or four times.

“With less than a doubling of the rate of illness, they are making claims of causation; and worse, without any foundation in research, EPA claims there is ‘no safe limit’ for exposure to many chemicals once the agency has established tumors can be produced in laboratory animals exposed to substances at unbelievably high doses, regularly, over extended periods of time, which does not at all correspond to real-world exposure,” Dunn said. “It's called the ‘linear no threshold’ theory of toxicology, which is a misuse of science in a way that ultimately negatively impacts human health.”